I have recently bought this adventure as I am hoping to run it in the future.

I have had a quick review of the adventure last night and have some questions:

1. The Tiefling thugs have a Strength of 8. How have people found this negative to work in game?
Because it seems like it relegates them to mere speed bumps. Even goblins usually have more strength and threat to them

Is speed bumps all they are supposed to be?

Or has anyone reworked their stat block (to at least give them 10 in Srength)?

2. The Sorcerers with Charm Person. Do people think this is important for their challenge level.

Because I am a relatively new DM and the whole issue of how Charm Person should work when cast on a PC seems like a highway to disaster (especially amongst my group who will potentially metagame or furiously debate the point)

Can the spell be easily swapped out without the fight losing anything from it's designed difficulty? Does anyone have any particularly good recommendations for an alternate spell?

Get used to it...you will find some fights in the book REALLY stupid and some REALLY good. Then there will be a few where you go, "Hmm the creator of this fght clearly wanted me to take every PC out of the game here without much of a fight..."

Yeah, if you think Charm Person will be an issue for your group, just swap it out for a more straight-forward spell.

And like Are said, the tieflings use crossbows, so the strength isn't a huge issue. They're tough enough that if the PCs play very poorly they can be a threat, but for the most part it's the stronger enemies that are a threat in this adventure.